Flat roof device. Design features of flat roofs

This option for arranging the upper part of the building is used, as a rule, in the construction of "high-rise buildings", as well as various administrative, industrial, warehouse and some other buildings: pavilions, showrooms and the like. Despite the fact that flat roof there are a number of disadvantages, this does not reduce the popularity of such a design, including in private housing construction.

Benefits of flat roofs

Firstly, the installation of a flat roof can be carried out independently, and not to invite assistants or hire professionals, as, for example, when constructing a roof of complex configuration (, four-pitched, etc.). Consequently, their work will not have to be paid (we are not talking about large areas where it will be problematic to cope alone).

Secondly, the construction of such a roof gives significant savings both in terms of materials (money) and time (coverage area is much smaller than with pitched equipment). You do not have to make numerous calculations or order a project (which will cost a lot), collect complex system rafters, install jibs, sprigs and so on. In addition, there are no restrictions on the choice of the type of roofing.

Thirdly, a flat surface is much easier to maintain and repair, which also gives tangible savings in the future.

Fourth, a choice of arrangement options. A flat roof can either serve only as a traditional "cover" for the house, or be used (inverted). For example, greenhouses are mounted on it, summer gardens, solariums and the like. There are even heliports. This fully compensates for the inconvenience due to the lack of an attic room.

disadvantages

• Increased requirements for waterproofing. Since the roof is located horizontally, water falling in the form of precipitation will stagnate on it. You can use eg.
• Debris will constantly accumulate (for example, fallen leaves), so such a roof will have to be serviced more often.
• Lack of an attic (mansard) space

What to consider

• The maximum load that the roof will experience (for roof structure). This includes the weight of the frame itself, roofing material, layers of insulation and insulation, as well as possible snow cover. In addition, you need to rely on the fact that the roof must withstand the weight of people who will subsequently walk on it.
• The purpose of the building and the possibility of further use of the surface (for example, terrace equipment). Depending on this, the type of overlap is determined.

Work technology

The simplest version of a flat roof is when reinforced concrete slabs are laid (for example, a garage, a barn). Everything is extremely simple here. On the surface, the so-called " layered cake»: vapor barrier, if necessary - insulation material, waterproofing layer. For the equipment of the latter, roll materials are most often used.

Insulation of a reinforced concrete slab can be done by pouring a layer of expanded clay and equipping a cement screed on top. Slag and some other materials are also used.

Traditionally, roofing material is used for waterproofing, which is covered with bituminous mastics on top. It should be noted that this material will last no more than 5 years, and then you will have to deal with repairs. It is more expedient to lay polymeric materials, for example, membranes, as a "waterproofer". Liquid rubber is also great.

Since the installation of plates requires the involvement special equipment, at independent device flat roof can be equipped with the simplest truss system from wood.

First of all on the top bearing walls supports are laid - Mauerlats. The most commonly used material is timber. It must be taken into account that these structural elements must be rigidly fixed in order to exclude the possibility of their horizontal displacement.

Therefore, metal pins are immured in their upper end surfaces along the entire length of the walls. Their length is calculated so that after the installation of the Mauerlat they rise above the beam by about 5 cm. Threads must be cut at their ends.

If the masonry is old, then a “tape” of concrete mortar. After that, in each wooden blank pre-drilled holes with a diameter slightly larger than the cross section of the metal "fingers". First, strips of roofing material (or similar waterproofing material) are laid on the tape, and then Mauerlats. They are mounted on pins, and a washer is put on top of each, and with the help of a nut, the beam is securely fixed at the installation site.

Next, floor beams are laid. It should be noted that the roof should protrude beyond the dimensions of the house by 50 - 60 cm (required overhang). This will protect both the walls and the blind area from water flowing from it, as well as from raindrops.
Device load-bearing frame. Depending on the type, it can be either solid (boards, slabs) or cellular (battens).

• Vapor barrier.

• Insulation. For flat roofs there is a nuance. Absence attic space deprives such a building of an “air cushion” from above. Therefore, insulation is carried out both outside and inside. But at the same time, it is necessary to take into account the weight of such material, since it is an additional load on the truss system.

• Waterproofing.

• Roof covering.

• Overhang finishing.

This is only a general list of necessary activities. The technology for the production of work for each item depends on local conditions and on the selected materials.

• Any "wood" used in construction must be well dried. The moisture in its structure gradually “leaves” (natural shrinkage of the material), which leads to a change not only in the volume of the workpiece, but also to its deformation (for example, twisting).
• Wood has two significant drawbacks - it burns and is prone to decay. Therefore, before using it, all wooden parts of the structure are pre-treated with flame retardants and antiseptics. It is better to spend money on these funds than to suffer with frequent repairs later.
• When installing Mauerlats, you need to constantly monitor their horizontalness with the help of building level. Otherwise, the roof will turn out to be skewed. If necessary, either the tape is leveled, or a rigid lining is made under the Mauerlat.
• To exclude stagnant water on the roof, it is advisable to make it with a certain slope (approximately 3 0 - 5 0). As a rule, the decrease goes towards the rear side of the building. To do this, the height of the front Mauerlats increases, so the floor beams will fall with a slope.

The device of a flat roof is one of the most simple and convenient ways installation.

Therefore, the construction of a flat roof is quite often involved in the construction of residential buildings and industrial-type buildings.

The article discusses the functions, advantages and disadvantages of a flat roof according to wooden beams, stages of its installation (destruction, creation of a drain and a roofing pie, installation of parapets).

Depending on the type of roofing, the flat roof device is divided into 4 separate types:

• exploited;
• unexploited;
• inversion;
• traditional.

Positive and negative points

The device of a flat roof in frame houses on wooden beams is gaining more and more popularity every year.

The installation technology of such an exploited roof is so simple that with a small volume construction works, even a non-professional can cope with this task.

Even though it is called flat, it is still not horizontal.

When recreating it, a small technological bias is still very important - for 1 m of length it is 1.5-2.5%, provided that it is an exploited space.

In all other cases, this slope, according to SNiP, must be at least 3-10%.

If we are talking about the service life of the coating (corrugated board) on frame house, then it directly depends on the professionalism of the builders who were involved in its construction.

But at the same time, an important role is played by the choice of materials, the properties of which must correspond not only to the terrain, but also to other parameters.

In regions with moderate rainfall, corrugated roofs are most often constructed. Laying corrugated board on a flat roof is carried out directly on the floor beams.

It is important that the technology of installation and installation of flat roofs is observed, since any deviations from the specified standards, when using low-quality materials, can cause a decrease in the life of not only the roof, but the building itself as a whole.

Advantages:

• The device of a flat exploited roof based on rolled materials is considered an example of simplicity and minimalism, from an architectural point of view:
• Smaller area, and therefore savings in materials;
• Long service life of a roof from a professional flooring;
• Simple mounting technology and device flat cover from corrugated board;
• Convenience during professional examinations and repair of the exploited roof of a house from corrugated board;
• The possibility of using this site for a cafe or a green lawn;
• Stability of roll materials under any weather conditions.

Important conditions:

• High strength, which is very important during periods of heavy snowfall, when it is under pressure from snow and ice. This indicator must be taken into account when the roof is in operation;
• The use of materials when constructing a flat roof of a private house, which are able to withstand severe frosts and hot sunlight;
• The roof must be heat-insulated and fireproof, according to SNiP.

Operated and non-operated types of coatings

The technology of the device of a flat exploited roof implies the wear resistance and strength of rolled materials.

Due to this, it is able to be homogeneous even with fairly strong uneven and long-term loads.

Such a roof is suitable for walking on it, like a corrugated roof.

Non-exploited corrugated roofing is less wear-resistant, due to the lack of a rigid base in it.

But at the same time, a corrugated roof is more durable and does not need special care.

The device of operated flat roofs today is carried out using the following materials:

• Use of roll materials;
• The use of polymer membranes;
• Use of asphalt and bituminous mastics;
• Application of materials with liquid rubber.

The device of a flat exploited roof made of corrugated sheets differs in the design of a roofing pie from any other roof.

A vapor barrier is laid on top of the ramp.

To date, several subspecies are known:

• directed;
• membrane;
• bulk.

Flat roof mounting scheme using different materials consists of the following steps:

• Vapor barrier with glassine, polyethylene film, roofing material;
• Warming with mineral wool, expanded clay, polystyrene;
• Gravel spreading device;
• The device of a bulk cement-sand or asphalt concrete screed;
• Priming screed;
• Device roll roofing from polymeric membranes;
• Installation of overhang and parapet from steel sheets;
• External drainage system;
• Installation of funnels for water drainage.

How is a flat roof slope created?

The formation of stagnant zones, thawing and freezing, the appearance of vegetation adversely affects the roof, reducing its service life.

The decompression device helps to combat these phenomena. SNiP, regulating their device, contribute to the flow of water to the funnels from the parapet, even with damage to the roof.

There are several ways to create a slope on the exploited roof of a house:

• With backfill heaters;
• On heat-insulating plates;
• With the help of concrete mixtures.

The most economical option for flat roofing on wooden beams is the use of wedge-shaped styrofoam slabs.

This method is considered the least laborious, in contrast to the demolition using a cement-sand screed. The most optimal is the creation of a slope with a slope of 1.7-2%.

All construction and repair work is carried out strictly in accordance with the requirements of SNiP, and therefore soft roof— is no exception.

For construction companies, SNiP are the rules that guide the performance of work. Only in this case the coating will be durable and strong.

To work with each of the rolled roofing materials, there are typical technological maps, which describes detailed diagram flat roof construction process.

When creating a typical map, the requirements of SNiP for roofing must be taken into account.

So, when installing a flat roof of a house from rolled materials, SNiP II-26-76 is considered the main regulatory document.

In addition, the provisions of SNiP 3.04.01-87 are used, with a description of finishing and heat-insulating coatings, as well as requirements governing labor safety when performing such work.

Drainage system on a flat roof

The device of an internal drain on flat roofs of the house helps to eliminate moisture. by the most the best option is the organization of internal drainage.

To do this, the funnels are evenly distributed over the surface of the roof, carrying out the removal of water flows during heavy snowfalls and showers, preventing flooding. This is the main function of the drain.

The system of internal drainage and slopes is an indicator of roof care.

This suggests that it is important to inspect funnels, cleaning them of dirt, leaves, and also repair or replace them in a timely manner.

The device of an internal drain and slope is a sanitary standard, the miscalculations of which are carried out specifically for each individual case.

Initially, many people believe that the device of an internal drain and slope is not so important for residential buildings, however, a large functional load is assigned to it.

SNiP provides for the mandatory presence of an internal drain to protect structures from adverse effects.

It is important to perform the internal drainage device correctly, since if even small mistakes are made, there may be problems later.

At the time of drawing up the construction project, it is important to plan for the presence of a drain.

Making a roofing cake

The installation conditions of the operated roof provide for the mandatory presence of a roofing pie, as it prevents heat loss. Protecting the roof from overheating is also one of the functions of the roof threshold.

The device of a roofing cake for a flat roof implies the presence of such layers:

• base;
• steam insulation;
• insulation;
• hydroprotection.

Each of the elements of the roofing pie performs its function. If the work on creating a roofing pie was performed in violation of the instructions, then the entire system will not function correctly. As a result, the work will have to be completely redone.

During the creation of a roofing pie, the following points are performed:

• steam isolation;
• creating a crate;
• insulation installation;
• work with waterproofing;
• ventilation system.

Subject to all the requirements for the construction of a roofing pie, you can be sure of a positive result of the work carried out.

Still an unusual decoration country cottages – flat roof. It is believed that flat roofs are intended only for urban development or for industrial buildings. But it's not. The roofs of houses in historic neighborhoods are often pitched. And at a private house you can make a flat roof.

Now we will look at what it is, what are the advantages / disadvantages and how to make a flat roof with your own hands.

Types of flat roof

Structurally, flat roofs are divided into two main types: on beams and those in which at the base concrete slab.

Flat roofs are never completely flat, there is still a small angle (within a few degrees). This is necessary for the flow of water. Otherwise, it will stagnate on the roof.

Most often, internal drains are arranged on flat roofs: funnels are mounted in the roof, risers from them pass through interior spaces. Funnels are placed on the lower part of the roof, at the rate of one riser per 150-200 squares.

The waterproofing around the funnels is reinforced, cable heating is also recommended (so that the water in the riser does not freeze). If a flat roof without a parapet, and a decent angle (from 6 degrees), the drainage system can be a standard outdoor one, as for pitched roofs: gutter and pipes.

Roofs are subdivided according to functionality, the device of the roofing pie and the type of coating. Here are some of the main varieties:

• The unexploited roof is flat. It is built solely for the sake of originality and economy of material. It does not need to strengthen the structure.

• Operating flat roof. Can be used for any purpose, from placement outdoor pool and ending with a parking lot.

The type of overlap depends on the intended purpose: it is obvious that with high expected loads, the base should be a concrete slab. But this does not mean that the entire building should be brick or concrete. For example, a flat roof wooden house can also be exploited. Of course, it cannot be used as a heliport, but it is quite possible to arrange a solarium, set up a garden or put up a gazebo for tea drinking. Of course, a sparse crate cannot be made, only a solid one.

• traditional roofing. The classic version of the roofing cake: a waterproofing layer on top of the insulation, the base is concrete, for the outflow of water - expanded clay concrete (sloping screed).

• Inversion roof. Here, the insulation lies on top of the waterproofing and protects it from damage. The floor can be finished with paving or ceramic tiles, you can also plant a lawn here. A mandatory requirement for an inversion design is an angle of 3-5 degrees.

Roofs are attic and non-attic. Both types have their advantages: the presence of an attic allows you to place all the necessary communications on it (ventilation pipes, expansion tank heating, etc.), a barren roof can be made exploitable.

One of the options for a non-attic design is a flat combined roof: attic floor combined with the roof, the lower side is the ceiling in the living room.

note

With a house height of ten meters or more, as well as on exploited roofs in without fail install a parapet. For exploited - not less than 1.2 meters.

If the roof is not in use, and the cottage is low, you can make a flat roof without a parapet or install fencing bars instead, or even do without them.

General arrangement of a flat roof

It is obvious that the devices used for roofs for various purposes will differ:

The most common coating is flat roofing. This is cheapness, simplicity and high laying speed, excellent waterproofing. Most cheap material, which can be covered with a flat roof - roofing material.

The disadvantages of rolled materials (and roofing material in particular) are low durability, low mechanical strength. For exploited roofs "with high traffic" tiles are preferable.

A flat roof made of corrugated board and a flat roof made of corrugated board can only be made in a non-exploited version and with the necessary slope. When choosing a material, you need to read the instructions for the model: some types of profiled sheets and metal tiles can be laid on roofs with a slope of less than 11 degrees.

Some brands of corrugated board can also be used as a base for an unexploited roof, instead of plywood or concrete slab.

There are other coating materials for unused roofs:

• Polycarbonate;

Pros and cons of flat roofs

Advantages:

• Original look. Flat roofs in cottages are rare.
• Possibility of exploitation.
• Flat roof - easy installation and savings on materials. But it depends on how you plan to operate the roof. And then the construction will cost even more than the expensive pitched roof from ceramic tiles.
• Laying, maintenance, repair on a flat roof is easier than on a slope.
• Flat roofs are windproof, pitched roofs have windage.

Minuses:

• A flat roof leaks more often than a pitched one. It is necessary to constantly monitor the condition of the waterproofing layer.
• The need to clear the roof of snow.
• Flat roll roofing requires more frequent repairs and change of coating than metal profile, tiled and other pitched.

So which roof is better, flat or pitched? Exclusively a matter of taste.

Building a flat roof

Consider the option when the profiled sheet is used as the basis of the roof:

1. Sheets are laid on the beams (rafters). The step between the rafters depends on the profile. For example, for load-bearing profiles with a corrugation height of 6-7.5 centimeters (H60, H75), the step between the beams is 3-4 meters.

2. Laying a vapor barrier film. The film is laid with an overlap, the joints must be sealed with mounting tape.

3. Thermal insulation. Mineral wool boards are usually used for this purpose. Please note that the corrugation depressions also need to be filled with insulation.

4. Waterproofing. For this purpose, a polymer film is suitable. If the insulation is mineral wool, you can also use built-up waterproofing, because. cotton wool is a non-combustible material.

5. Finishing coat. You can also use fused. A roll is slowly rolled out over the roof, heating it with a burner along its entire length. The deposited coating is pressed against the roof and smoothed out.

6. On flat roofs it is possible to lay the built-up roof in several layers.

In other cases, a flat roof over wooden beams is arranged more traditionally: a solid plywood or OSB crate is nailed onto the beams, laid roofing cake(vapor barrier + basalt wool), guide the waterproofing layer and roll roofing.

If you are interested in a flat roof with a more complex device, please contact us: we will perform a roof of any complexity quickly and at an affordable price.

Flat roof - common architectural solution in civil, industrial and private construction. The device of a flat roof has its own characteristics, but main principle consists in the fact that the waterproofing layer must be a continuous carpet with certain technical characteristics. The design of roof structures must be carried out in accordance with the current SNiP.

The structure of the roofing cake

Looking at the structure in section, this species roof is a multilayer structure, which includes:

• flat base;
• vapor barrier layer;
• insulation;
• waterproofing.

The base of a flat roof can be reinforced concrete slab ceilings, or metal profile construction. Depending on the type of base, the material for the remaining components of the roofing pie and the methods of its installation are selected.

The vapor barrier layer is made of rolled or bituminous materials. It prevents the penetration of moisture from the premises into the heat-insulating layer of the roof structure.

A wide range of materials are used as insulation for flat roofs, including:

• mineral wool;
• expanded clay gravel;
• polystyrene boards;
• cement-sand screed.

The waterproofing layer is traditionally made of bitumen-based roll materials. Special mastics or a PVC membrane can also be used.

The waterproofing carpet must have a certain elasticity in order to withstand mechanical deformations of the base and temperature changes.

The structure of the pie depends on functional features roofs. The following types of roofing are distinguished:

• traditional;
• ventilated;
• operated;
• inversion.

Flat roof slope

According to SNiP, when installing a flat roof structure, it is necessary to provide for its slope of 1-4 °. This design of flat roofs avoids the accumulation of water on the surface of the coating. For waterproofing, not only prolonged stagnation of water in certain areas is dangerous. Severe deformation and destruction outer coating roofing is the result of repeated repetition of the process of freezing and thawing of accumulated moisture. Can be used for sloped roofs various materials. The choice depends on their technical characteristics and installation features.

Lightweight concrete with bulk polymer filler (in particular, extruded polystyrene) is one of the most popular materials. It is quite simple to install, the resulting design has high strength. But the use of this material for leveling should be provided for at the design stage of the building, since the significant weight of the concrete used increases the load on the floor, walls and foundation of the building.

It also has similar characteristics lightweight concrete with a filler of perlite or expanded clay. This material is cheaper, but its weight is even greater, while the resulting roofing cake is less durable.

The device of a flat roof can be carried out with the use of monolithic heaters, which allow to perform a slope. In this case, the prepared surface is mounted sheet material(mineral wool, expanded clay sheets, etc.). Fastening can be carried out on a strong, tenacious glue, which excludes the displacement of sheets over time. Dowels with a plastic spacer can also be used - it is advisable to exclude metal contact with the base of the roof so that the roofing cake does not have cold bridges.

The most time-consuming is the construction of a roof using bulk materials for a break. It is difficult to pour a layer of loose insulation (expanded clay or perlite) with concrete, observing the required angle of inclination of the roof plane, since the granules can move.

An effective, but expensive option for leveling is the laying of foam concrete, followed by the application of a layer of fiber-reinforced concrete. A cake with such a heat-insulating layer is designed for long-term operation. This technology requires the involvement of experienced professionals.

In accordance with SNiP, the slope of the roof is carried out towards the water intake funnels (if there is an internal drain), or towards the water intake gutters external system catchment, which must be attached under the roofing carpet or on outer wall building.

Roof knots

In order for the roofing pie to be reliably protected from external influences, Special attention should be given to the places of its adjunction to building structures– parapets, walls, pipes, external parts ventilation systems etc. There are various nodes of a flat roof, first of all, this is a node:

• adjoining;
• overhang;
• passage through the roof.

The nodes are installed on a reinforced concrete base in places where the roofing pie adjoins the vertical structure with a cut. Manufacturers of roofing materials often develop their own systems, which may have certain design features.

The node must ensure the tightness of the joint and its thermal protection, therefore, the installation of the nodes should be taken very carefully.

The device of an unexploited flat roof

The most common design is the traditional soft roof. In the section, it consists of a bearing base slab, a vapor barrier layer, thermal insulation made of sheet mineral wool and a waterproofing carpet made of rolled bitumen-containing material. The advantages of this design include low cost and easy installation.

More practical non-exploited roofs are made using modern materials. PVC membrane waterproofing is very popular. Its installation can be performed in any season, as the membrane is resistant to low and high temperatures. In addition, if the thermal insulation layer has managed to accumulate moisture during installation, the membrane allows it to evaporate. At the same time, the material has high water-repellent properties. In the process of mounting the canvases into a single whole, special welding equipment without an open flame is used.

Covering an unused flat roof can be done using mastic. This is a liquid material that is applied over a rigid, even heat-insulating layer. Mastic is made on the basis of flexible, hydrophobic polyurethane resins. outdoors, through certain time after applying in an even layer, it polymerizes, forming a continuous rubber-like membrane. The device of such waterproofing allows you to reliably protect the roofing pie from moisture penetration.

A popular technology is the use of built-up waterproofing. This affordable option in terms of price and quality ratio - the durability of such a roof is from 25 years. Bitumen-polymer material based on a rot-proof canvas creates a heavy-duty waterproofing layer. Using given material can be performed.

Operating roof device

This design of a flat roof is much more expensive to install, but allows you to profitably use additional space. Today, this type of roof is widely demanded for equipment. sports grounds, green areas, cafes, parking lots, etc. Installation of a reinforced roof is also necessary if heavy objects, including equipment, are to be installed on the roof. In accordance with SNiP, the roof structure must withstand an uneven high load, that is, it must not deform in limited areas of the area. The section of a flat exploited roof differs from the usual one by the presence of a rigid base in the pie or a special screed over the waterproofing layer. Such a coating excludes punching of the waterproofing carpet with its subsequent destruction.

Inversion Coating Features

Structure inverted roof fundamentally different from other types of roofs. When it is arranged, first of all, a waterproofing layer is mounted on the base. In the context of a roofing pie, it looks like this: base slab, waterproofing, insulation, drainage layer, geotextile. This design allows you to protect waterproofing material from the damaging effects of ultraviolet radiation and temperature extremes, mechanical damage. Geotextiles, in turn, provide insulation protection. Used as the outer layer paving slabs. Such a roof can withstand high loads, including being used as a parking lot.

Flat roofs, their types and designs can be classified:

• According to the purpose of the surface. It can be operated and non-operated.
• According to the method of laying the roofing cake. It can be traditional and inversion.
• By type of construction. It can be attic and non-attic.
• Separately, ventilated and non-ventilated structures are distinguished.

exploited roof

The exploitable flat roof can be used as a parking lot, helipad, tennis court, swimming pool, green roof and just a terrace. In any case, it is necessary to calculate the possible load on the roof.

• Load from operation (weight of a person, car, water in the pool, etc.).

In some cases, the roof is subjected to a pressure of 20 tons per square meter.

Also, due to the nature of the flat roof device, it is highly exposed to ultraviolet rays.

Together, these factors mean that the choice building materials for such a roof must be approached with special care.

The device of the roofing pie of the operated roof is as follows:

• Reinforced concrete floor slab.
• Sloping layer. It is made of slag, concrete, expanded clay, wedge-shaped mineral insulation and other similar materials. From above it is fixed with a concrete screed. Slope up to 3%. It is necessary for high-quality water drainage in the required direction. Sloping is always arranged in front of waterproofing to ensure that water flows through it.
• Leveling concrete screed.
• Waterproofing. It is made of bituminous, polymeric, PVC materials and sealants. Roofing material is often used, laying it in two layers, while it is important that the joints of the upper and lower rows do not coincide.
• thermal insulation. Keeps indoors warm in winter and cool in summer. Requires a careful approach to the calculation of thickness. In the event of a mistake, condensation inside the room cannot be ruled out. If not an inversion type of roof is used, but a traditional one, the insulation must be resistant to steam. Otherwise, there must be resistance to water absorption.
• drainage layer. Given the technology of a flat roof, water must flow over the surface in drainage trays. But in other cases, moisture can get into the joints between tiles used as a finishing paving element, or soak into the ground when using a green roof. So that the elements of the roofing cake do not get wet, they arrange a drainage layer that drains water in the right direction.
• Further, it all depends on the type of roof being used. If this green roof- geotextiles are laid, which will not allow the roots of plants to destroy the roofing cake. If this is a roof-terrace, or a parking lot, a concrete screed under the tile, or other finishing material, goes behind the drainage layer.

Please note that when using a traditional roof, the order of the elements of the roofing cake changes. A vapor barrier is laid along the slope-forming layer, then a heater, and only then waterproofing.

The advantages and disadvantages of this method are discussed below.

Unexploited roof

An unused flat roof is notable for its economy. It is not designed to withstand any load other than snow. This allows less careful approach to the choice of building materials.

The device of a roofing pie of this type of roof is as follows:

• Reinforced concrete floor slab. Instead, it is allowed to use profiled sheets with a large wave height, such as H-153 and H-158.
• Slope layer.
• Vapor barrier.
• Thermal insulation.
• Waterproofing.
• Ballast layer of gravel. The thickness of such a layer should be from 10 to 20 centimeters. It is necessary to protect the waterproofing from UV rays and to prevent fires.

Once again, we draw your attention to the fact that the layers of steam, heat and waterproofing can change places depending on the type of roofing used.

traditional roof

The device of a flat roof according to the traditional type has been used for a very long time. In this case, the roofing pie will look like this:

• Slope layer.
• Vapor barrier. It is necessary to protect the insulation from steam emanating from the room. Otherwise, even in the case of one percent moistening of the heat-insulating layer, a significant increase in thermal conductivity occurs. It is made of specialized vapor barrier membranes and films.
• Thermal insulation. It is allowed to use almost all types of insulation, even with a low percentage of moisture resistance.
• Next, according to the traditional drawing of the roof of a flat roof, a layer of waterproofing should be laid. Please note that it must certainly be of high quality, since it is absolutely not protected from temperature extremes.

The advantages of a traditional roof are that it guarantees the protection of the heat-insulating layer from getting wet. Firstly, it allows you to use the entire range of roofing insulation. Secondly, the insulation will not lose its thermal conductivity characteristics, which means that a comfortable temperature regime will always be maintained in the room.

At the same time, this flat roof design compromises waterproofing. It is most susceptible to temperature differences, which leads to its accelerated aging. Also, the insulation does not protect the waterproofing from external power loads, which again negatively affects its service life. In general, this type of roof is less durable and requires fairly frequent repairs.

inverted roof

It is a more progressive type of flat roof device. Assumes the device of the following roofing pie:

• Reinforced concrete floor slab, or corrugated board.
• Slope layer.
• Leveling concrete screed.
• Primer for waterproofing, for a better fit. During this process, the screed is carefully inspected for cracks and water bubbles. Cracks are covered with mortar, water bubbles are removed.
• Waterproofing.
• Thermal insulation.
• Further, either a drainage or ballast layer, depending on whether the roof will be exploited or not.

An inverted roof has the following advantages:

• Protection waterproofing film from temperature fluctuations. As a consequence, this extends the life of the film in particular, and the life of the roof in general.
• The insulation redistributes the power loads on the waterproofing in such a way that it does not affect it.
• Extruded polystyrene foam, which is commonly used as thermal insulation for this type of roof, is cheaper than mineral wool used for traditional roofing.
• The inverted design of a flat roof allows more repairs, if necessary, replacement, or adding insulation.

There are also disadvantages, which include:

• It is permissible to use heaters only with closed cells in order to prevent them from getting too wet.
• The need to install a more complex design of gutters.

attic roof

The technology of a flat roof with an attic implies the possibility of using two types:

1. The attic roof is a light superstructure, and the attic floor acts as the main supporting structure.
2. The attic floor and the attic roof are independent of each other and are able to withstand power loads equally well.

The advantages of a roof with an attic are:

• Possibility of continuous monitoring of the tightness of the waterproofing layer.
• The ability to regularly monitor the condition of the insulation.
• Insulation can be laid after the roof has been installed.
• The attic itself performs the function of thermal insulation.

The disadvantages include:

• impossibility mechanical cleaning from snow, provided that the attic roof is used as a light superstructure. Instead, the attic is blown with hot, dry air, which ensures that the snow melts from above and gradually melts.
• This type of roof is more expensive.

roofless roof

More popular is the bare roof. She:

• It costs less than an attic.
• Easier to install.
• Provides snow melting by conducting heat from the room.

A non-attic flat roof also has a significant drawback:

• There is no way to timely determine the violation of the waterproofing layer. These damages appear as a wet spot on the ceiling, making it impossible to determine the exact location of the leak.

Ventilated and non-ventilated roof

Roof ventilation is arranged between the insulation and the waterproofing layer. Thus, constant air circulation is achieved, which ensures the constant dryness of the insulation. Used in the traditional type of roofing cake.

When installing ventilation, it is important to adhere to the following recommendations:

• The height of the vent is at least 1/30 of the width of the building.
• Hole diameter not less than 1/150 of the total roof area.
• The air inlets must be lower than the outlets.
• The holes are evenly distributed across the width of the entire building.

In turn, a non-ventilated roof does not require the creation additional elements flat roof roofs. But this somewhat shortens the service life of the heat-insulating material.